Optimization of the exhaustive hydrodistillation method in the recovery of essential oil from fresh and cured betel leaves (Piper betle L.) using the Box–Behnken design

The optimization of extraction by the Box–Behnken design of response surface methodology, chemical composition, antioxidant activity (AA), and total phenolic content (TPC) of fresh and cured betel leaf essential oil (BLEO) was reported. A quadratic polynomial equation developed by multiple regression analysis revealed that the models were highly significant with R² = .98 and p < .0001. At optimal extraction conditions of extraction time (140 min), extraction temperature (100°C) and leaf to water ratio (1:1.5 g/L), 0.35% and 0.48% of fresh and cured BLEO yield were obtained. Thirty‐three and thirty volatile compounds were identified from fresh and cured BLEO by gas chromatography‐mass spectroscopy, accounting for 96.4% and 93.96% of the total oils, respectively. Eugenol, estragole, linalool, α‐copene, and anethole with different percentages were accounted to be major components. Fresh BLEO exhibited strong antioxidant effects on DPPH and TPC than cured leaf EO. Both the EOs explored that AA had a positive correlation with their phenolic contents. Practical applications The present study explores the effect of optimized exhaustive hydrodistillate condition on the analysis of chemical composition and AA of essential oil (EO). The findings of optimized extraction embodied in the present research can be scaled up for commercial and industrial purposes. Both fresh and cured BLEO may be used in the food industry as a natural food preservative and flavoring agent. It can be also used for various herbal, medicinal, and therapeutic products. The main identified compounds such as eugenol, estragole, and linalool are the most valuable for food and pharmaceutical industries. Eugenol was found to be the highest amount in the extracted EO that can be used as a local anesthetic in dentistry as an ingredient in dental cement for temporary fillings.